I would buy tires from Tire Rack-on-line vendor
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I've been buying tires from Tirerack for the last 15 years. I was hooked buy one of my outside sales rep. The savings 30% to 150%, and when I bought my first set of four I saved 100%. Freight is about forty bucks for a set four tires if you have the tires shipped to a commercial address you will save a little on the freight. I get my tires installed at Mercedes dealership(Mercedes dealership has those nice plastic coated lead balancing weights) or pep-boys.
One thing to note, I would buy 45 PSI tires in these high gas price times instead of the usual 35 PSI tire. What I've noticed on these 45 PSI tires is the side-walls are much thicker. Most tires are triple "A" rated (Temperature-Tread-wear-Traction) Temperature and Traction very important, and should always be "A" rated. The DOT stamp (on every side wall of every tire) should be no more than a year old(four digits-first two digits week(s) and second two digits year)
Martin